Simulium novemarticulatum Takaoka and Davies 1995

Phasuk, J., Chanpaisaeng, J., Adler, P. H. & Courtney, G. W., 2005, Chromosomal and morphological taxonomy of larvae of Simulium (Gomphostilbia) (Diptera: Simuliidae) in Thailand, Zootaxa 1052, pp. 49-60 : 58

Simulium novemarticulatum Takaoka and Davies 1995

The original description of this species was based on female specimens collected from Malaysia ( Takaoka and Davies 1995). Through association of larvae, pupae, and reared females from the same stream in Khao Yai National Park, we confirmed the first known collection of the former two life stages. The arrangement of gill filaments of this species is similar to that of S. siamense . The larva is distinguished from that of S. siamense by its deep postgenal cleft, with the apex reaching the posterior margin of the hypostoma, and by two types of setae on the abdominal cuticle: thick, dark setae with 2 or 3 branches and minute, dark, delicate setae with 2–4 branches ( Fig. 2 I). The eight gill filaments of this species are arranged in groups of 3 + 3 + 2 from dorsal to ventral ( Fig. 3 C). However, the stalk of the lower pair is variable in length. The antenna of the adult is composed of 9 articles, whereas the antenna of S. siamense has 11 flagellomeres.

Three of 77 larvae were analyzed for major landmarks. The IIS arm has the ring of Balbiani near the subterminal bulge ( Figure 1 J).

Figures

FIGURE 1. Idiograms of chromosome arm IIS for 12 Simulium species in subgenus Gomphostilbia from Khao Yai National Park, showing relative locations of Ce, centromere; RB, ring of Balbiani; Bu, bulge; Sh, shoestring. A, Simulium angulistylum. B, S. decuplum. C, S. dentistylum. D, S. gombakense. E, S. siamense. F, S. sp. A. G, S. asakoae. H, S. sheilae. I, S. sp. nr. sheilae. J, S. novemarticulatum. K, S. sp. B. L, S. sp. C.

FIGURE 2. Photographs of setae on abdominal cuticle of Simulium species in subgenus Gomphostilbia. A, Simulium angulistylum. B, S. decuplum. C, S. dentistylum. D, S. siamense. E, S. sp. A. F, S. asakoae. G, S. sheilae. H, S. sp. nr. sheilae. I, S. novemarticulatum. J, S. sp. B.

FIGURE 3. Photographs of gill filaments of Simulium species in subgenus Gomphostilbia. A, Simulium angulistylum. B, S. sp. A. C, S. novemarticulatum. D, S. siamense. E, S. sheilae. F, S. sp. nr. sheilae.